sponsored by psychohistorian.org

DOCdb

Deep Sky Observer's Companion – the online database

 

Welcome, guest!

If you've already registered, please log in,

or register an observer profile for added functionality.

List:

log in to manage your observing lists

 browse:

 

 position:

 

 next:

 

 options:

summary

rename

prune

trim

remove

close

copy

combine

plan

bookmark

load

new

delete

marathon

favourite!

Full database:

Entire DOCdb database of 18,816 objects.

 browse:

 position:

NGC 6556 (14,965 of 18,816)

 next:

oc gc pln bn dn gx gxcl ast aka lost

Object:

list

bookmark

finder chart

altitude today

altitude (year)

 search:

½°, , in DOCdb

show browsing

NGC 6556

NGC 6556, ESO 456-61, h 3732, GC 4380

RA: 18h 09m 57.5s
Dec: −27° 31′ 29″

Con: Sagittarius
Ch: MSA:1415, U2:339, SA:22

Ref: NGC/IC

(reference key)

Type: open cluster

Mag: B=?, V=?

Size: 15′ x 12′
PA: ?

History and Accurate Positions for the NGC/IC Objects (Corwin 2004)

NGC 6556. The problems with this object began with Sir John himself and his summary description published in the GC, then copied faithfully into the NGC. That description makes the object "F, vL, cE, lbM, rr." On the other hand, JH's original notes read "Cl VI. An oval patch comprised within limits of the field, barely resolvable into infinitely minute points, but which, without attention, appears as a great nebula 15' l; 12' br; hardly bM."

Howe saw it the same way 65 years later: "I see nothin in the entire region except thousands of the minutest stars." Dreyer summarized this in the IC2 Notes simply as "No nebulosity (Ho)."

The object is actually part of the complex region of star clouds and obscuring dust clouds near the Galactic Center. JH's position points to an otherwise unremarkable part of the Milky Way, comprised of, as both he and Howe saw, "... thousands of the minutest stars." I've adopted JH's position, and his description above is apt.

Historical observations

John Herschel (1847) Cape Observations

Discovered by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "Cluster VI An oval patch comprised within limits of the field, barely resolvable into infinitely minute points, but which, without attention, appears as a great neb 15' long, 12' broad; hardly bM."

Published comments

Sulentic & Tifft (1973)

The RNGC (Sulentic and Tifft 1973) notes that this is a nonexistent object. Their coded description reads NF S.

Favourite lists

Lacaille's catalogue

The Messier objects

Dunlop's catalogue

The Bennett objects

The Caldwell list

Named DSOs

Object search

First search phrase

    and

Second search phrase

Type of object to include:

open cluster
globular cluster
planetary nebula
bright nebula
dark nebula
galaxy
galaxy cluster
asterism & stars
unverified/lost
nova

The Bug Report

DOCdb is still in beta-release.

Known issues, feature requests, and updates on bug fixes, are here:

> Bug Report

Feedback

Found a bug? Have a comment or suggestion to improve DOCdb? Please let us know!

> Contact us

Help!

DOCdb is a free online resource that exists to promote deep sky observing.

You could help by sharing your observations, writing an article, digitizing and proof-reading historical material, and more.

> Find out more

Everything on DOCdb.net is © 2004-2010 by Auke Slotegraaf, unless stated otherwise or if you can prove you have divine permission to use it. Before using material published here, please consult the Creative Commons Attribution-Non-Commercial-Share Alike 2.5 License. Some material on DOCdb is copyright the individual authors. If in doubt, don't reproduce. And that goes for having children, too. Please note that the recommended browser for DOCdb is Firefox 3.x. You may also get good results with K-Meleon. Good luck if you're using IE. A successful experience with other browsers, including Opera and Safari, may vary.